Norway is considering whether to ask the US to extend the deployment of Marines to the country.

The US has already expressed interest in an extension, Norway's defense minister said in March.

Marines in Norway are focused on training for cold-weather operations — training motivated in part by increasing tensions with Russia.

Norway's government may ask the US to extend a Marine Corps deployment in the country, Foreign Minister Ine Eriksen Soereide told Reuters.

"We are currently in a phase where we are discussing different options, but I think from our point of view it has been very useful and very successful," she said.

Contingents of about 300 Marines from various units have been stationed in Norway for six-month deployments. The first rotational force arrived at Vaernes in central Norway in January 2017 — the first time a foreign force was stationed on Norwegian soil since World War II (though Norway and the Marine Corps have managed weapons and equipment stored in caves there since the Cold War).

The deployment has already been extended, with the initial rotational force being replaced by another in August 2017. The roughly 330 Marines in the country are now scheduled to stay until the end of the year.

Marines in Norway have focused on cold-weather training, doing exercises with Norwegians and other partner forces. Some of those exercises have taken place near Norway's border with Russia, which has criticized the Marines' presence in Norway. Russia's embassy in Norway told Reuters that extending the Marines' presence would worsen Norway's relations with Moscow and could raise tensions on NATO's northern boundary.

"The Americans have been very happy with how things have played out," Soereide said. "They do see after many years where they had a lack of winter training and expertise of wintry conditions ... they are now, to a larger extent, able to deal with the cold."

Norwegian Defense Minister Frank Bakke-Jensen said in March that the US was interested in continuing the deployment and that his government hoped to make a decision on it in the coming months.

The Pentagon "would like to extend the [deployment] and they would like to see whether we could increase," he told Defense News during a visit to Washington. "We will look into it and give them an answer in, before the summer ... that's my ambition."

Marine Corps Commandant Gen. Robert B. Neller said in January that US forces "haven't been in the cold-weather business for a while."

"Some of the risks and threats there, there is a possibility we are going to be there," he said at the Center for Strategic and International Studies in Washington.

During a visit with Marines stationed in Norway at the end of 2017, Neller was more blunt in his assessment.

Telling Marines in the country to remain ready to fight at all times, he said he foresaw a "big-ass fight" on the horizon, according to Military.com. "I hope I'm wrong, but there's a war coming," Neller said. "You're in a fight here, an informational fight, a political fight, by your presence."

Neller added that he believed the US military's focus would shift away from the Middle East in the coming years, with the Marines in particular focusing on the Pacific and Russia.

Norway is one of many countries that have expressed concern about an increasingly assertive Russia, especially in the years since the Russian occupation of Crimea.

US Marines with Marine Rotational Force 17.2 play a game of bulldog to keep warm in the harsh weather during exercise White Claymore in Bardufoss, Norway, February 7, 2018. US Marine Corps/Cpl. Careaf L. Henson

In 2017, Norway decided to buy five P-8 maritime surveillance aircraft, bringing it closer to the US and the UK, with whom it maintained a surveillance network over the North Atlantic during the Cold War. Norway has also teamed up with Germany to buy new submarines. In November, Oslo accepted three F-35 fighters, the first to be permanently stationed there.

Concerns about Russia military action as well as the potential for US retreat from the NATO alliance have boosted political support for Norway's increased defense spending, but opposition leaders have still criticized the way it's been financed and questioned what role US troops will have.

"There has been no real debate about the role of US forces. There is concern that we may be looking at a significant shift in Norwegian defense policy without an informed debate," Audun Lysbakken, leader of the Socialist Left party, said in late 2017.

Soereide, Norway's foreign minister, told Reuters that Oslo did not see Russia as a military threat and that the risk of war in the Arctic was "low." But she did say her government saw challenges poised by Russia actions, particularly in the area of civil society, rule of law, and democracy.